values

Returns a Set view of the values contained in this map.
The set is backed by the map, so changes to the map are reflected
in the set, and vice-versa. If the map is modified while an iteration
over the set is in progress (except through the iterator's own
remove operation), the results of the iteration are undefined.
The set supports element removal, which removes the corresponding
mapping from the map, via the Iterator.remove,
Collection.remove, removeAll,
retainAll and clear operations. It does not
support the add or addAll operations.